The present invention relates to a combination of a pneumatic tire and a vehicle wheel, where the wheel has a rigid rim that is provided with essentially radially inwardly extending rim flanges, with the rim furthermore being provided, on its radially outer side, with support surfaces for operation in an essentially uninflated state of the tire, and, on its radially inner side, with respective recessed mounting portions for the beads of the tire, which is made of elastomeric material, i.e. rubber or rubber-like synthetic material, and has a carcass that is anchored in the tire beads by being looped about pull and compression-resistant bead cores thereof, with the beads being disposed on rim seating surfaces provided on the radially inner side of the rim next to the rim flanges.
Vehicle wheel and tire assemblies of this general type are disclosed, for example, in German Offenlegungsschrift No. 30 00 428 and German Offenlegungsschrift No. 36 21 849. Such wheel and tire assemblies are characterized by a high driving comfort and by favorable emergency operation characteristics when, for example, a flat tire is encountered. Due to the arrangement of the tire beads on the radially inner periphery of the rim, the rim flanges are disposed in the interior of the tire, so that the sidewalls of the tire can spring or deflect inwardly in an unobstructed manner, and can bulge laterally outwardly.
The tire beads rest against the rim in essentially three areas, namely on the radially inner seating surfaces of the rim ring, against the perpendicular faces of the rim flanges, and against the radially inner surfaces of the rim flanges. Due to the carcass forces that act at the bead cores, radially inwardly directed forces as well as pivot moments are generated at the tire beads; these forces must be absorbed at the three aforementioned seating surfaces on the rim. It is sometimes not easy to optimally select the proportions for these seating surfaces relative to the overall bead seat on the rim. These difficulties increase even more due to the unavoidable tolerances encountered during the mass production of rims and tires.
To resolve the indicated problems, German Offenlegungsschrift No. 36 21 849 proposed the use of an annular and/or disk-shaped support body for absorbing radial forces and pivot moments of the bead at the radially inner surface of the bead, at least in the axially inner region, with this support body being centered relative to the axis of rotation of the rim at non-resilient portions of the vehicle wheel. However, this solution requires a further component in the form of the annular or disk-shaped support body, and furthermore centering means must be provided on the rim.
It is therefore an object of the present invention to provide an improved bead seat in a more straightforward manner.